CRITIC'S NOTEBOOK; Another Question in Thrillers: Where Did the Logic Go?

Alfred Hitchcock, as is well known, gave the playful name McGuffin to the element in a movie's plot that propels the action. A McGuffin can be one of two types, an event that unleashes a series of subsequent events (as in ''Strangers on a Train'') or (as in, say, ''Frenzy'' or ''Psycho'') a secret, a mystery, that must be revealed by the end. Either way, the unfolding of the intrigue must follow logically from the McGuffin, as it always did in Hitchcock. Things made sense.

What if they don't? The question is relevant because more and more, it would seem, thrillers, however technically brilliant, do not make sense -- or, at least, do not flow from a tight interior logic.

Well, call me a pedant, but my reaction to a thriller that fails logically is always disappointment, a sense of having been cheated. I would appeal for good old logical consistency, a high level of plausibility, as a necessary ingredient in thrillers, in movies as well as in books (where the same problem exists).

A thriller should be a dramatic intensification of the possible as well as a tightly constructed puzzle. Even if the tale is farfetched, it needs to follow logically from its own premise and and give the appearance of something that could happen in the real world.If a thriller is unmoored from a sense of the possible, it loses the capacity to inspire the dread that makes both for suspense and intellectual coherence.

The current example of a movie with logical gaps as big as Manhattan is the much-acclaimed box office hit ''Ronin,'' directed by John Frankenheimer and starring Robert De Niro. As Anthony Lane of The New Yorker wrote, ''Ronin'' has three of the best car chase scenes of recent years. Mr. Lane also allows that there are some ''loose ends,'' but he treats them, as other critics do, as minor flaws in what he regards as a basically good work.

I agree that ''Ronin'' is good in many ways. But my overall reaction was to feel let down, to believe that what could have been a tingling entertainment, like Mr. Frankenheimer's masterpiece, ''The Manchurian Candidate,'' was ruined by its absence of logic.

''Ronin'' involves a group of former intelligence agents from various countries who take on a lucrative freelance assignment consisting of stealing a mysterious metallic suitcase from its well-armed owners. The suitcase stealers, the Ronin of the title, proceed to perpetrate mayhem and murder as they carry out their task. The suitcase is also sought by shadowy groups of Irish terrorists and of unidentified Russians who have planted secret agents among the Ronin. Indeed, these groups will stop at nothing to recover the object, whose original owners, by the way, are equally determined to hold on to it.

The idea of several secretly competing groups, of three different levels of betrayal, is marvelous, and it leads to a great deal of action-filled skulduggery. But a fundamental question remains unanswered. What, as the De Niro character asks several times, is in the suitcase? We never find that out. Does it matter? Clearly a lot of people, including most of the critics, don't think it does, and they give essentially two reasons.

One is that the De Niro character, as it turns out, doesn't really care about the suitcase after all. He is really interested in infiltrating the Irish group so that he can eliminate an Irish terrorist standing in the way of the negotiations in Northern Ireland. This, of course, leaves a gaping question: Why, if the suitcase was so important to the Irish and the Russians, are the Americans indifferent to it? But never mind.

The second, more important argument is that the heart of the movie lies in the layers of distrust and betrayal among the Ronin, while all else is relatively unimportant. Mr. Lane found it refreshing that, as he put it, the McGuffin turns out to be a question of lost luggage. That it is not some standard, overworked thriller device -- a lode of enriched uranium, for example -- gives it a witty post-modernist touch. It is as if Mr. Frankenheimer is saying, We are going to create a cinema of absolute purity, free of the drag and dross of a conventional McGuffin.

That is a strong argument, but a thriller without a real McGuffin is like a placebo, a pill with no real chemical effect. Another problem is that much of the action in ''Ronin,'' from its small gestures to the way it solves its own puzzle, seems both illogical and unrealistic. The bits and pieces of illogic accumulate, turning the film into a kind of gritty fairy tale full of automobile acrobatics but depriving it of a machine with working parts..

Why, in the opening scene, for example, does the De Niro character hide his gun or go to inspect the men's room? He does these things for no reason other than the director's interest in creating a sense of foreboding, but without plausible reasons emerging for his behavior, the foreboding is contrived.

Another example: People are always going into hiding in this movie, and they are always found effortlessly, as if by magic, by those looking for them. At one point, three of the dramatis personae get hold of the suitcase and disappear in Paris. The De Niro character and his partner (played by Jean Reno), still in the south of France, go to a mysterious French former agent living in a gated chateau, where he spends his time making miniature models of famous Japanese battle scenes. ''I'll find them for you,'' he tells the defeated pair and, sure enough, presto! Next scene: The De Niro character and his partner are staking out the battered Parisian hideaway.

''Ronin'' is certainly not unusual in this absence of connective tissue. I am not speaking of the unserious thrillers, like the ''Lethal Weapon'' series, that dispense even with the pretense of logical plausibility, but of serious thrillers like, say, ''The Peacemaker,'' which is full of political absurdities and unexplained occurrences.

In ''The Peacemaker,'' for example, a Serb extremist is pushed to an act of nuclear terrorism because his family is gunned down before his eyes in ''sniper alley'' in Sarajevo during the Bosnian civil war. No critic whom I read felt it worthy of note that in reality the Serbs were the snipers of sniper alley. The Muslims were generally the victims.

Whatever other qualities of excitement or drama these movies may have, the absence of logic, their disconnection from real-world plausibility, deprives them of the essential ingredient of satisfying suspense. When writers and directors have recourse to what are essentially magical interventions, they might as well be making Road Runner cartoons.

You need an escape from an impasse? Have the Road Runner paint a tunnel on the side of the cliff. You need to find some disappeared rivals? Turn to some savant who makes toy soldiers in a castle, and he will do the job without providing a hint to the viewer of how the feat was accomplished.

And to require recourse to a magic wand is the cinematic equivalent of defying the laws of gravity. It helps to get the moviemaker to the next scene, but it leaves the audience with its feet suspended in midair.